1. Field of the Invention
This invention relates to reed valves for compressors and vacuum pumps.
2. Discussion of the Prior Art
Reed valves for vacuum pumps and compressors, collectively referred to herein as pumps, are well known. These valves typically include a thin reed or flapper which opens or closes in response to a pressure difference across it. For intake reed valves, this allows for the intake of gas (typically air) to the working chamber on the intake stroke of the pump, and for an exhaust reed valve, the expulsion of gas from the working chamber on the exhaust stroke, during the pumping process.
Prior designs in general had a valve plate with an intake port and an exhaust port bored through it provided between the working chamber and a head of the pump. An intake flapper was provided over the intake port on the working chamber side of the plate and an exhaust flapper was provided over the exhaust port on the head side of the plate. Fasteners were typically used to secure both valve flappers to the valve plate.
For both valve flappers, the fasteners required extra steps in assembly, for example, boring and tapping holes, threading and tightening screws, etc. In addition, for the intake flapper on the working chamber side of the valve plate, fasteners required a clearance volume, to avoid interference with the piston, which detracted from the swept volume in the working chamber and therefore detracted from the pumping efficiency with which the unit could be operated.
In other arrangements, the intake and discharge flappers were formed in one piece and laid in the same or nearly the same plane. With these arrangements, a substantial clearance volume also existed adjacent to the intake flapper. Therefore, a need exists for a reed valve which is easy to assemble, inexpensive and reliable, and in particular for an intake reed valve having these advantages and which also helps reduce the clearance volume in the working chamber.